1. Field of the Invention
The present invention relates to a method for transmitting uplink control information in a wireless communication system, and in particular, to a method for transmitting uplink control information on a physical uplink control channel.
2. Description of the Prior Art
The long term evolution (LTE)/LTE-Advanced project is the largest new technology research and development project started by the 3rd Generation Partnership Project (3GPP) in recent years. Such type of technology with the orthogonal frequency division multiplexing/frequency division multiple access (OFDM/FDMA) technology as core is considered as a “quasi-4G” technology.
According to LTE Rel-8/9/10, uplink L1/L2 control signaling is used to dynamically indicate a downlink and uplink transmission channel. A user equipment uses an uplink control channel, that is, a physical uplink control channel (PUCCH), to report periodic L1/L2 control signaling. The uplink control signaling includes hybrid automatic repeat request-acknowledgements (HARQ-ACK) of a downlink-shared channel (DL-SCH) transmission block for reception and channel state information (CSI) related to downlink channel conditions and a scheduling request, and indicates that the UE is in need of uplink resources for uplink-shared channel (UL-SCH) transmission. Generally, the channel state information further includes a rank indicator (RI), a channel quality indicator (CQI), and a precoding matrix indicator (PMI), where the CQI and the PMI are generally applied together.
With the development of LTE/LTE-Advanced, the coordinated multi-point (CoMP) technology is introduced. The user equipment needs to report a downlink status of multiple transmission points in a cooperating set, so as to assist a base station to coordinate downlink scheduling between different transmission points and execute channel-dependent scheduling. How to ensure that the user equipment can correctly transmit uplink control information of multiple transmission points on a physical uplink control link so as to avoid a conflict between control information of different transmission points has become a problem to be solved in the industry.